The BMW M8 is a spectacular machine. Its 4.4-liter twin-turbo V8 produces over 600 horsepower with 553 lb-ft of torque, and the car itself is arguably one of the best-looking in BMW's current range. While it's a great car and a suitable replacement for the old 6 Series, it's a bit of a letdown in some respects. You see, when BMW said that the 8 Series would return, we were hoping for something more like the E31 shape. This was a beautiful car that had plenty of advanced features, and an M8 version would have been phenomenal. As fanatics already know, there actually was an M8 version, but it was hidden from public view for decades. Now, BMW is looking back at what could have been, had the car been unleashed.

You can't talk about old-school BMWs without peeking under the hood. In the E31 M8 prototype, there's a 6.0-liter V12 with a carbon fiber intake plenum, and it would have catapulted BMW's image into supercar territory. In the beginning of the 1990s when this car would have been launched, BMW's most powerful car was the 850Csi, producing 375 horsepower. The M8, on the other hand, was tuned to deliver 631 hp, giving it a top speed of over 186 mph. Helping it glide through the air were aerodynamic wing mirrors, while wider arches than the regular E31 allowed for better handling.

BMW also got rid of the pop-up (and down) headlights, rather integrating all forward lighting into the bumper, reducing wind resistance and complexity. It was way ahead of its time with the wheels too, which were made from carbon fiber-reinforced plastic, while the glass-reinforced plastic of the doors, trunk lid, and hood all helped contribute to a low curb weight of just under 3,200 pounds.

That racing theme was carried over to the interior, where you'd find grippy bucket seats with racing harnesses and loads of Alcantara. The E31 M8 was a wonder, and it's astonishing to think that today's turbocharged, electronics-full M8 provides similar power figures and a near-identical top speed. We just wish we could experience that N/A V12 in a modern car.